Chemical composition, antiproliferative, antioxidant and antibacterial activities of essential oils from aromatic plants growing in Sudan

Cymbopogon schoenanthus (L) extract ameliorates high fat diet-induced obesity and dyslipidemia via reducing expression of lipogenic and thermogenic proteins

Globally, obesity has become one of the major health problems. This study was conducted to evaluate the anti-obesity potential of Cymbopogon schoenanthus methanolic extract (CS) in rats. Fifty male Wistar rats of six to eight weeks old, 100-120 g body weight (BW) were randomly assigned into 5 groups (n = 10): The control group was fed a basal diet. CS-group was supplied with basal diet and orally given CS (200 mg/kg BW) for 12 weeks. HFD-group was fed a high-fat diet (HFD) for 18 weeks. HFD + CS-group was fed on HFD and CS HFD then CS-group was fed HFD for 12 weeks then shifted to basal diet and CS for another 6 weeks. Phytochemical analysis of CS indicated the presence of various terpenes and flavonoid compounds. Among the compounds characterized are quercetin, apigenin, luteolin, orientin, eudesmene, cymbopogonol, caffeic acid, coumaric acid, and linolenic acid. Supplementation of HFD significantly increased the body weight, levels of serum triacylglycerol, total cholesterol, very low-density lipoprotein, low-density lipo-protein (HDL), glucose, serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities. In addition, HFD up-regulated the protein expression of uncoupling protein (UCP)-1 in both brown and white adipose tissue; and the expression of hepatic mRNA of sterol regulatory element-binding protein (SREBP)-1c and SREBP-2. However, it decreased the serum level of HDL, and protein expression level of UCP-1 in both brown and white adipose tissue. Treatment of HFD-fed animals with CS extract either concurrently (HFD + CS-group), or after obesity induction (HFD then CS-group) significantly reversed all HFD-induced alterations in body weight; food intake; serum biochemical profile (including hyperglycemia, dyslipidemia); and tissue gene expressions. These results indicate that CS methanolic extract ameliorated HFD-induced obesity, serum biochemical, hepatic, and adipose tissue gene expression alterations. CS extract accomplished these effects mostly through its various identified bioactive compounds which have been proven to have anti-obesity and anti-diabetic activities.

Andrographolide: A Diterpenoid from Cymbopogon schoenanthus Identified as a New Hit Compound against Trypanosoma cruzi Using Machine Learning and Experimental Approaches

American Trypanosomiasis, also known as Chagas disease, is caused by the protozoan Trypanosoma cruzi and exhibits limited options for treatment. Natural products offer various structurally complex metabolites with biological activities, including those with anti-T. cruzi potential. The discovery and development of prototypes based on natural products frequently display multiple phases that could be facilitated by machine learning techniques to provide a fast and efficient method for selecting new hit candidates. Using Random Forest and k-Nearest Neighbors, two models were constructed to predict the biological activity of natural products from plants against intracellular amastigotes of T. cruzi. The diterpenoid andrographolide was identified from a virtual screening as a promising hit compound. Hereafter, it was isolated from Cymbopogon schoenanthus and chemically characterized by spectral data analysis. Andrographolide was evaluated against trypomastigote and amastigote forms of T. cruzi, showing IC50 values of 29.4 and 2.9 μM, respectively, while the standard drug benznidazole displayed IC50 values of 17.7 and 5.0 μM, respectively. Additionally, the isolated compound exhibited a reduced cytotoxicity (CC50 = 92.8 μM) against mammalian cells and afforded a selectivity index (SI) of 32, similar to that of benznidazole (SI = 39). From the in silico analyses, we can conclude that andrographolide fulfills many requirements implemented by DNDi to be a hit compound. Therefore, this work successfully obtained machine learning models capable of predicting the activity of compounds against intracellular forms of T. cruzi.

Antibacterial activity and action mechanism of curcusionol from Carex siderosticta Hance against Ralstonia nicotianae

BACKGROUND

Tobacco bacterial wilt is a typical soil-borne disease caused by Ralstonia nicotianae, which causes huge losses in tobacco production every year. The crude extract of Carex siderosticta Hance was shown to have antibacterial activity against R. nicotianae during our search, and the natural antibacterial components were sought after using bioassay-guided fractionation of the compounds.

RESULT

Ethanol extract of Carex siderosticta Hance with the minimum inhibitory concentration (MIC) value of 100 μg/mL against R. nicotianae in vitro. The potential of these compounds as antibactericides against R. nicotianae were assessed. Curcusionol (1), showed the highest antibacterial activity against R. nicotianae with MIC value of 12.5 μg/mL in vitro. In the protective effect tests, the control effect of curcusionol (1) was 92.31 and 72.60%, respectively, after application of 7 and 14 days, at a concentration of 1500 μg/mL, being comparable to that of streptomycin sulfate at a concentration of 500 μg/mL, confirming that curcusionol (1) showed the potential for the development of new antibacterial drugs. RNA-sequencing, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis confirmed that curcusionol mainly destroys R. nicotianae cell membrane structure and affects quorum sensing (QS) to inhibit pathogenic bacteria.

CONCLUSION

This study revealed that the antibacterial activity of Carex siderosticta Hance makes it a botanical bactericide against R. nicotianae, while curcusionol as lead structures for antibacterial development is obvious by its potent antibacterial activity. © 2023 Society of Chemical Industry.

Modulatory effects of extract of Heinsia crinita against fructose/streptozotocin-induced oxidative stress in diabetic rat models

Oxidative stress plays a crucial role in the development of type 2 diabetes and the associated microvascular and cardiovascular complications. In the study, we have investigated the effects of Heinsia crinita (H. crinita) extracts on lipid peroxidation and oxidative stress responses using diabetic rats. Type 2 diabetes was induced with 10 % fructose/40 mg/kg body weight streptozotocin (STZ). H. crinita extract was administered at 200 and 400 mg/kg body weight twice daily for 21 days, in addition to metformin (MET: 500 mg/kg body weight) control. Molecular docking analysis was performed to determine the binding affinity of H. crinita extracts to the DNA binding domains of peroxisome proliferator-activated receptor (Ppar) and retinoid x receptor (Rxr) protein crystal structures, showing different binding affinities for putative active compounds from the plant. Fasting blood glucose (FBG), body and organ weight changes were determined showing that H. crinita extract induced an anti-hyperglycemic effect in the treated animals, with changes (either decrease or increase) in liver and kidney weights. A decrease in mRNA expression of peroxisome proliferator-activated receptors (ppar), sterol regulatory element-binding protein 1 (srebp-1c), liver x-receptor (lxr), retinoid x receptors (rxr), cytochrome p45041 (cyp4a1) and acyl-CoA oxidase (acox1) in diabetic animals were observed, compared to the control. A dose-specific decrease or increase in antioxidant enzymes (superoxide dismutase: SOD, catalase: CAT, reduced glutathione: GSH, glutathione peroxidase: GPx) transcripts and activity levels were also observed. We also observed exposure-specific decrease or increase of malondialdehyde (MDA) levels. Our data suggested that H. crinita extract possesses protective effects against diabetes-induced oxidative stress. These effects might be attributed to their binding and activation of nuclear receptors, indicating their cellular mode of action that is comparable to MET.

Phytochemistry, data mining, pharmacology, toxicology and the analytical methods of Cyperus rotundus L. (Cyperaceae): a comprehensive review

Cyperus rotundus L. has been widely used in the treatment and prevention of numerous diseases in traditional systems of medicine around the world, such as nervous, gastrointestinal systems diseases and inflammation. In traditional Chinese medicine (TCM), its rhizomes are frequently used to treat liver disease, stomach pain, breast tenderness, dysmenorrheal and menstrual irregularities. The review is conducted to summarize comprehensively the plant's vernacular names, distribution, phytochemistry, pharmacology, toxicology and analytical methods, along with the data mining for TCM prescriptions containing C. rotundus. Herein, 552 compounds isolated or identified from C. rotundus were systematically collated and classified, concerning monoterpenoids, sesquiterpenoids, flavonoids, phenylpropanoids, phenolics and phenolic glycosides, triterpenoids and steroids, diterpenoids, quinonoids, alkaloids, saccharides and others. Their pharmacological effects on the digestive system, nervous system, gynecological diseases, and other bioactivities like antioxidant, anti-inflammatory, anti-cancer, insect repellent, anti-microbial activity, etc. were summarized accordingly. Moreover, except for the data mining on the compatibility of C. rotundus in TCM, the separation, identification and analytical methods of C. rotundus compositions were also systematically summarized, and constituents of the essential oils from different regions were re-analyzed using multivariate statistical analysis. In addition, the toxicological study progresses on C. rotundus revealed the safety property of this herb. This review is designed to serve as a scientific basis and theoretical reference for further exploration into the clinical use and scientific research of C. rotundus.

Graphical Abstract

Supplementary Information

The online version contains supplementary materials available at 10.1007/s11101-023-09870-3.

GC-MS Profiling and Biomedical Applications of Essential Oil of Euphorbia larica Boiss.: A New Report

The present study explored Euphorbia larica essential oil (ELEO) constituents for the first time, obtained via hydro-distillation by means of Gas Chromatography-Mass Spectrometry (GC-MS) profiling. The essential oil was screened in vitro against breast cancer cells, normal cell lines, α-glucosidase, carbonic anhydrase-II (CA-II), free radical scavenging and in vivo analgesic and anti-inflammatory capabilities. The GC-MS screening revealed that the ELEO comprises sixty compounds (95.25%) with the dominant constituents being camphene (16.41%), thunbergol (15.33%), limonene (4.29%), eremophilene (3.77%), and β-eudesmol (3.51%). A promising antidiabetic capacity was noticed with an IC50 of 9.63 ± 0.22 μg/mL by the ELEO as equated to acarbose with an IC50 = 377.71 ± 1.34 μg/mL, while a 162.82 ± 1.24 μg/mL inhibition was observed against CA-II. Regarding breast cancer, the ELEO offered considerable cytotoxic capabilities against the triple-negative breast cancer (MDA-MB-231) cell lines, having an IC50 = 183.8 ± 1.6 μg/mL. Furthermore, the ELEO was also tested with the human breast epithelial (MCF-10A) cell line, and the findings also presumed that the ELEO did not produce any damage to the tested normal cell lines. The ELEO was effective against the Gram-positive bacteria and offered a 19.8 ± 0.02 mm zone of inhibition (ZOI) against B. atrophaeus. At the same time, the maximum resistance with 18.03 ± 0.01 mm ZOI against the fungal strain Aspergillus parasiticus was observed among the tested fungal strains. An appreciable free radical significance was observed via the DPPH assay with an IC50 = 133.53 ± 0.19 µg/mL as equated to the ABTS assay having an IC50 = 154.93 ± 0.17 µg/mL. The ELEO also offered a substantial analgesic capacity and produced 58.33% inhibition in comparison with aspirin, a 68.47% decrease in writhes, and an anti-inflammatory capability of 65.54% inhibition, as equated to the standard diclofenac sodium having 73.64% inhibition. Hence, it was concluded that the ELEO might be a natural source for the treatment of diabetes mellitus, breast cancer, analgesic, inflammatory, and antimicrobial-related diseases. Moreover, additional phytochemical and pharmacological studies are needed to isolate responsible chemical ingredients to formulate new drugs for the examined activities.

Chemistry and Bioactivity of Croton Essential Oils: Literature Survey and Croton hirtus from Vietnam

Using essential oils to control vectors, intermediate hosts, and disease-causing microorganisms is a promising approach. The genus Croton in the family Euphorbiaceae is a large genus, with many species containing large amounts of essential oils, however, essential oil studies are limited in terms of the number of Croton species investigated. In this work, the aerial parts of C. hirtus growing wild in Vietnam were collected and analyzed by gas chromatography/mass spectrometry (GC/MS). A total of 141 compounds were identified in C. hirtus essential oil, in which sesquiterpenoids dominated, comprising 95.4%, including the main components β-caryophyllene (32.8%), germacrene D (11.6%), β-elemene (9.1%), α-humulene (8.5%), and caryophyllene oxide (5.0%). The essential oil of C. hirtus showed very strong biological activities against the larvae of four mosquito species with 24 h LC₅₀ values in the range of 15.38-78.27 μg/mL, against Physella acuta adults with a 48 h LC₅₀ value of 10.09 μg/mL, and against ATCC microorganisms with MIC values in the range of 8-16 μg/mL. In order to provide a comparison with previous works, a literature survey on the chemical composition, mosquito larvicidal, molluscicidal, antiparasitic, and antimicrobial activities of essential oils of Croton species was conducted. Seventy-two references (seventy articles and one book) out of a total of two hundred and forty-four references related to the chemical composition and bioactivity of essential oils of Croton species were used for this paper. The essential oils of some Croton species were characterized by their phenylpropanoid compounds. The experimental results of this research and the survey of the literature showed that Croton essential oils have the potential to be used to control mosquito-borne and mollusk-borne diseases, as well as microbial infections. Research on unstudied Croton species is needed to search for species with high essential oil contents and excellent biological activities.

Screening and Identification of Croton Fruit Poisoning in Food Using GC-MS and HPLC-MS/MS

Croton fruit poisoning was successfully identified through a series of chromatographic technologies. A suspected compound named 2-methyl-butenoic acid was screened out using gas chromatography-mass spectrometry, and the hydrolysate of isoguanosine in soup sample was further detected by high performance liquid chromatography-tandem mass spectrometry. The identification of croton fruit poisoning was confirmed basing on these laboratory tests together with the clinical symptoms of the patients. Especially, the false-negative result and the interferences were successfully excluded through simulation test, spectral analysis and chromatographic separation technique. Such study is significant for croton poisoning identification and provides beneficial references for disposing untargeted food poisoning incident.

The antioxidant and antidiabetic potentials of polyphenolic-rich extracts of Cyperus rotundus (Linn.)

In this study, the rhizome of Cyperus rotundus L was investigated for its antioxidant and antidiabetic effects using in vitro and in silico experimental models. Its crude extracts (ethyl acetate, ethanol and aqueous) were screened in vitro for their antioxidant activity using ferric-reducing antioxidant power (FRAP) and 1,1-diphenyl-2-picrylhydrazyl (DPPH), as well as their inhibitory effect on α-glucosidase enzyme. Subsequently, the extracts were subjected to Gas Chromatography-Mass Spectrometry (GC-MS) analysis to elucidate their possible bioactive compounds. Furthermore, computational molecular docking of selected phenolic compounds was conducted to determine their mode of α-glucosidase inhibitory activity. The aqueous extract displayed the highest level of total phenolic content and significantly higher scavenging activity in both FRAP and DPPH assays compared to ethyl acetate and ethanol extracts. In FRAP and DPPH assays, IC₅₀ values of aqueous extract were 448.626 µg/mL and 418.74 µg/mL, respectively. Aqueous extract further presented higher α-glucosidase inhibitory activity with an IC₅₀ value of 383.75 µg/mL. GC-MS analysis revealed the presence of the following phenolic compounds: 4-methyl-2-(2,4,4-trimethylpentan-2-yl) phenol, Phenol,2-methyl-4-(1,1,3,3-tetramethylbutyl)- and 1-ethoxy-2-isopropylbenzene. Molecular docking study revealed 1-ethoxy-2-isopropylbenzene formed two hydrogen bonds with the interacting residues in the active site of α-glucosidase enzyme. Furthermore, 4-methyl-2-(2,4,4-trimethylpentan-2-yl) phenol had the lowest binding energy inferring the best affinity for α-glucosidase active site. These results suggest the possible antioxidant and antidiabetic potential of Cyperus rotundus.Communicated by Ramaswamy H. Sarma.

The association study of chemical compositions and their pharmacological effects of Cyperi Rhizoma (Xiangfu), a potential traditional Chinese medicine for treating depression

ETHNOPHARMACOLOGICAL RELEVANCE

Cyperi Rhizoma (CR) derives from the rhizome or tuber of Cyperus rotundus L. of Cyperaceae. It is an herbal medicine which has been widely used in different healthcare systems like in China, India, Iran, and Japan. In Chinese medicine, CR could promote the flow of Qi in the Liver and Sanjiao channels, regulate menstruation and alleviate pain. Clinically, CR is used for depression, flatulence, hypochondriac pain, and dysmenorrhea. Thus, it has a long history and significant curative effect for the treatment of various Qi stagnation symptoms.

AIM OF THIS REVIEW

This review focuses on explaining the major antidepressant mechanisms of CR, and assessing the shortcomings of existing work. Besides, clinical applications, pharmacological effects and their corresponding chemical compositions and quality control of CR have been researched.

MATERIALS AND METHODS

The search terms "Cyperus rotundus L." was used to obtain the literatures from electronic databases such as Web of Science, ScienceDirect, PubMed, and China National Knowledge Infrastructure (CNKI). The information provided in this review to illustrate material basis of CR were only limited to papers which reported on the chemical compositions and pharmacological effects simultaneously.

RESULT

The study showed that CR has significant application in Qi stagnation, like depressed liver, stomach, and bowel disorders, etc. in different countries or districts. Aqueous extract, EtOH extract, essential oil, total oligomeric flavonoids and five other extracts were effective constituents displaying pharmacological activities such as antibacterial, antioxidant, neuroprotective, antihemolytic, and anti-inflammatory effect. 41 kinds of specific components like α-cyperone, nootkatone exhibited corresponding pharmacological activities mentioned above. Different concentrations of ethanol extract, essential oil, decoction of CR and monomer composition like α-cyperone, rotunduside G had anti-depressant effects.

CONCLUSIONS

In the present study, we have provided scientific information and research developments on traditional uses, phytochemical compositions and corresponding pharmacological activities, and quality control status on CR. The antidepression effect and its corresponding chemical compositions were generalized separately. The pharmacological activities studies should be more focused on the reflection of traditional clinical values. CR could be a significant potential herbal medicine to develop antidepressant drugs with lower side effects.

Quality Status Analysis and Intrinsic Connection Research of Growing place, Morphological Characteristics, and Quality of Chinese Medicine: Cyperi Rhizoma (Xiangfu) as a Case Study

Materials and Methods

The macroscopic characteristics of CR as well as its moisture, ethanol extract, essential oil, total ash, and acid-insoluble ash contents were examined and calculated. In addition, qualitative identification and quantitative determination of α-cyperone, cyperotundone, and nootkatone were simultaneously performed, and a high-performance liquid chromatography (HPLC) fingerprint chromatogram was established. Inductively coupled plasma mass spectrometry and gas chromatography methods recorded in ChP were used to measure the contents of residues of heavy metal and deleterious elements as well as residues of organochlorine pesticide, respectively. Hierarchical cluster analysis and typical canonical correlation analysis were performed using Origin 9.1 and SPSS 23.0 to explore the correlation between CR's growth area, morphological characteristics, and quality.

Results

Of the 47 batches of CR analyzed, only 4 collected from the province of Shandong had a flat appearance, which did not accord with the macroscopic characteristics of CR. Overall, only 4 batches met ChP standards for CR. In addition, 30 and 38 batches did not meet the requirements for moisture content and essential oil content, respectively. The similarity values of HPLC fingerprints ranged from 0.568 to 0.986. Results of hierarchical cluster analysis for ethanol extracts, essential oil, α-cyperone, cyperotundone, and nootkatone and the HPLC fingerprints (total peak time and peak area) suggested that the samples could be classified into four clusters, with no significant difference in growth geographic areas among them. Results of canonical correlation analysis indicated that the first canonical pair could represent the correlation between macroscopic characteristics (vector 1) and chemical quality (vector 2), with shorter diameter and length denoting lower ethanol extract content and higher nootkatone content in a single grain of CR.

Conclusions

Crude medicinal materials were collected and examined in this study to reflect the overall quality status of CR in China. The methods chosen to detect, calculate, and analyze the quality of CR were suitable to the investigation, and the results are crucial not only for estimating the current quality status of CR, but also for conducting further research into its cultivation, quality assurance, and commodity specification. Besides, this mode of investigation could be used to evaluate other medicines.

Chemical Profile of the Volatile Constituents and Antimicrobial Activity of the Essential Oils from Croton adipatus, Croton thurifer, and Croton collinus

The aim of this study was to determine the volatile phytochemical constituents and evaluate the antimicrobial activity of the essential oils of the leaves from Croton adipatus, Croton thurifer, and Croton collinus. Essential oils were extracted by hydro-distillation using the Clevenger extractor and the phytochemical analysis was determined by Gas chromatography-Mass Spectrometry (GC-MS). The antimicrobial activity was assessed using the agar diffusion and colorimetric broth microdilution methods against Staphylococcus aureus ATCC 25923, Bacillus subtilis ATCC 6633, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 9027, and Candida albicans ATCC The essential oils from C. adipatus, C. thurifer, and C collinus had 46, 38, and 35 volatile constituents respectively. The main compounds determined in C. adipatus were β-myrcene (18.34%), while in C. collinus was β-caryophyllene (44.7%), and in C. thurifer was an unknown component (C₁₀H₁₆: 22.38%). Essential oil of C. adipatus showed a MIC against B. subtilis (286.4 µg/mL) and C. albicans (572.8 ± 0 µg/mL); C. thurifer against S. aureus (296.1 ± 0 µg/mL) and B. subtilis (148 ± 0 µg/mL); and C. collinus against B. subtilis (72 ± 0 µg/mL) and C. albicans (576.2 ± 0 µg/mL). The three essential oils of Croton species demonstrated in vitro antimicrobial activity against a strain of bacteria or fungi.

Chemical Diversity between Three Graminoid Plants Found in Western Kenya Analyzed by Headspace Solid-Phase Microextraction Gas Chromatography–Mass Spectrometry (HS-SPME-GC-MS)

In recent work, it was shown that the graminoid plants Cynodon dactylon (Poaceae), Cyperus exaltatus (Cyperaceae), and Panicum repens (Poaceae) have an ovipositional effect on the malaria vector Anopheles gambiae in olfactometric bioassays. In order to get a view of the diversity of semiochemicals present in the environment of the vector during olfactometric trials, in the present work, the volatile profiles of these graminoid plants were analyzed using headspace solid-phase microextraction (HS-SPME) together with gas chromatography–mass spectrometry (GC-MS). In addition, one-way ANOVA comparison of compounds detected in two or more headspace samples are presented in order to provide a basis for comparison of compounds that could constitute a starting point for novel blends of volatile organic compounds to be tested as oviposition attractants.

Mechanistic support of traditional Persian medicine for the treatment of acne vulgaris: A scoping review

BACKGROUND

Acne vulgaris is one of the most prevalent skin diseases, which also contributes to many psychological problems. Despite the recent progress in the treatment of acne vulgaris, the necessity for discovering more effective solutions has motivated many lines of research on natural and medicinal plants. The Traditional Persian Medicine (TPM) introduced some plants and remedies for acne treatment. Given the universal welcome for herbal medicine, this review was performed to formally assess the evidence for herbal medicines for acne vulgaris in TPM.

METHODS

The medicinal plants used in this study for treating acne vulgaris were selected based on common references to the plants in five famous textbooks of TPM from different time periods. Then, the anti-inflammatory and anti-microbial effects of these medicinal plants were investigated according to the recent literature available in five electronic databases including Scopus, Web of Sciences, PubMed, Google Scholar, and Science Direct.

RESULTS

Twenty-one herbs were commonly references in traditional TPM texts as helpful for topical treatment of acne vulgaris. The data collected from the electronic databases demonstrated most of these plants (eg, Astragalus sarcocolla, Ficus carica, and Hordeum vulgare) have both anti-inflammatory and anti-microbial mechanisms, which may assist to treat acne vulgaris.

CONCLUSION

This scoping review demonstrated many medicinal plants recommended by TPM books have therapeutic potential for acne vulgaris via multiple mechanisms.

Application crude multienzyme extract from Aspergillus niger as a pretreatment for the extraction of essential oil from Croton argyrophyllus leaves

Leaves of Croton argyrophyllus contain essential oil with promising active components for the development of drugs and botanical insecticides. In this study, we evaluated the enzymatic pretreatment process to increase the extraction of essential oil from fresh and dried leaves of C. argyrophyllus. Pretreatment was carried out using a crude multienzymatic extract obtained via solid-state fermentation of forage palm by Aspergillus niger, and the extraction was performed by hydrodistillation. A Doehlert matrix was used to optimize the enzymatic pretreatment variables temperature and enzymatic extract. The effect of pretreatment time was also investigated. At optimum experimental conditions, 41.34°C, 140 min, and 130.73 mL of enzyme in 369.27 mL of water, the essential oil yield from fresh leaves subjected to enzymatic pretreatment increased by 9.35% and that from dry leaves by 6.77%. Based on chromatographic analysis (GC-MS), no compound was degraded in the extraction process. Micromorphological analysis confirmed the rupture of the glandular trichomes, favoring essential oil release. Therefore, enzymatic pretreatment associated with hydrodistillation increased the essential oil yield and is a promising application to obtain essential oil for therapeutic purposes without altering its composition.

HPLC-Based Activity Profiling for Antiprotozoal Compounds in Croton gratissimus and Cuscuta hyalina

In a screening of Sudanese medicinal plants for antiprotozoal activity, the chloroform fractions obtained by liquid-liquid partitioning from ethanolic extracts of fruits of Croton gratissimus var. gratissimus and stems of Cuscuta hyalina Roth ex Schult. exhibited in vitro activity against axenically grown Leishmania donovani amastigotes. This antileishmanial activity was localized by HPLC-based activity profiling. Targeted preparative isolation afforded flavonoids 1–6, 3-methoxy-4-hydroxybenzoic acid (7), and benzyltetrahydroisoquinoline alkaloids laudanine (8) and laudanosine (9) from C. gratissimus, and pinoresinol (10), isorhamnetin (11), (-)-pseudosemiglabrin (12), and kaempferol (13) from C. hyalina. The antiprotozoal activity of 1–13 against L. donovani (axenic and intracellular amastigotes), Trypanosoma brucei rhodesiense (bloodstream forms), and Plasmodium falciparum (erythrocytic stages), and the cytotoxicity in L6 murine myoblast cells were determined in vitro. Quercetin-3,7-dimethylether (6) showed the highest activity against axenic L. donovani (IC_50, 4.5 µM; selectivity index [SI], 12.3), P. falciparum (IC_50, 7.3 µM; SI, 7.6), and T. b. rhodesiense (IC₅₀, 2.4 µM; SI, 23.2). The congener ayanin (2) exhibited moderate antileishmanial (IC₅₀, 8.2 µM; SI, 12.2), antiplasmodial (IC₅₀, 7.8 µM; SI, 12.9), and antitrypanosomal activity (IC₅₀, 11.2 µM; SI, 8.9). None of the compounds showed notable activity against the intramacrophage form of L. donovani.

Mining Sudanese Medicinal Plants for Antiprotozoal Agents

Neglected tropical diseases are major health hazards in developing countries. Annually, up to 30 million people are affected by either Chagas disease, African trypansomiasis or leishmaniasis, and more than 200 million by malaria. Most of the currently available drugs have drawbacks in terms of toxicity, limited oral availability, development of resistance, or non-affordability. Tropical plants of the arid zones are a treasure chest for the discovery of bioactive secondary metabolites. This study aims to compile Sudanese medicinal plants, validate their antiprotozoal activities, and identify active molecules. We have performed a survey of medicinal plants of Sudan and selected 62 that are being used in Sudanese traditional medicine. From these, we collected materials such as leaves, stem, bark, or fruit. The plant materials were extracted in 70% ethanol and further fractionated by liquid-liquid partitioning using solvents of increasing polarity. This resulted in a library of 235 fractions. The library was tested in vitro against Plasmodium falciparum (erythrocytic stages), Trypanosoma brucei rhodesiense (bloodstream forms), Trypanosoma cruzi (intracellular amastigotes), and Leishmania donovani (axenic amastigotes). Active fractions were also tested for cytotoxicity. Of the 235 fractions, 125 showed growth inhibitory activity >80% at 10 μg/ml, and >50% at 2 μg/ml against at least one of the protozoan parasites. Plasmodium falciparum was the most sensitive of the parasites, followed by T. b. rhodesiense and L. donovani. Only few hits were identified for T. cruzi, and these were not selective. Contrary to expectation based on phylogeny, but in agreement with previous results, a large number of extracts displayed mutual activity against T. brucei and P. falciparum. HPLC-based activity profiling for selected active extracts was performed to identify the bioactive principles. Active compounds identified by dereplication were guieranone A from Guiera senegalensis J.F.Gmel.; pseudosemiglabrin from Tephrosia apollinea (Delile) DC; ellagic acid and quercetin from Terminalia leiocarpa (DC.) Baill.; and catechin, ethyl gallate, and epicatechin gallate from Vachellia nilotica (L.) P.J.H.Hurter & Mabb. Also the extracts of Croton gratissimus var. gratissimus and Cuscuta hyalina Roth ex Schult. exhibited promising antitrypanosomatid activity. This assessment provides a comprehensive overview of Sudanese medicinal plants and supports the notion that they are a potential source of bioactive molecules against protozoan parasites.

Chemical profile, antiproliferative, antioxidant, and enzyme inhibition activities and docking studies of Cymbopogon schoenanthus (L.) Spreng. and Cymbopogon nervatus (Hochst.) Chiov. from Sudan

Essential oils from the inflorescence of Cymbopogon schoenanthus and C. nervatus growing in Northern Sudan were examined for their chemical composition, antiproliferative activity against human breast carcinoma and human colon adenocarcinoma cell lines, antioxidant activity (phosphomolybdenum, antiradical, reducing power, and ferrous chelating), and enzyme inhibition activity against acetylcholinesterase butyrylcholinesterase, tyrosinase, α-glucosidase, and α-amylase. In silico study on the inhibition of tyrosinase and α-amylase was also performed. Piperitone (59.1%) and isomers of para-menthadienols (35.3%) were the main compounds in C. schoenanthus and C. nervatus oils, respectively. Oil from C. nervatus possessed higher antioxidant activity than that from C. schoenanthus except for its metal chelating ability. Both oils showed high antiproliferative activity. In silico study showed that trans-p-mentha-2,8-dien-1-ol and piperitone (both isomers) revealed the best docking scores for α-amylase and tyrosinase, respectively. In conclusion, oils from these two Cymbopogon species could be new natural agents with functional properties for food, cosmetics, and pharmaceutical industries. PRACTICAL APPLICATIONS: Recently, there is a growing tendency to replace synthetic oils by natural ones in the cosmetic, food, and pharmaceutical products. In this context, we investigated the chemical characterization and biological activities of two Cymbopogon species essential oils (C. schoenanthus (L.) Spreng. and C. nervatus). Antioxidant capacity, enzyme inhibition, and antiproliferative effects were tested for biological activities. Chemical characterization was identified by GC-MS. Based on our findings, the Cymbopogon species may be utilized as sources of natural bioactive agents in food industries.

Essential Oil From Psidium guajava Leaves: An Excellent Source of β-Caryophyllene

The purpose of this study was to investigate the chemical composition of the essential oil extracted from Psidium guajava leaves and to explore the medicinal value of β-caryophyllene in pharmaceutical science. The essential oils of P. guajava leaves were extracted by the hydrodistillation method, using a Clevenger-type apparatus and the chemical composition of essential oils was investigated by gas chromatography–mass spectrometry. The yield of extracted essential oils was 0.6% (w/w) dry weight. The main compounds found in the leaves were β-caryophyllene (20.34%), globulol (8.20%), trans-nerolidol (7.72%), aromadendrene (4.34%), cis-α-bisabolene (3.82%), tetracosane (3.68%), octadecane (3.66%), Z, Z, Z-1,5,9,9-tetramethyl-1,4,7-cycloundecatriene (3.44%), β-bisabolene (3.41%), limonene (3.09%), octacosane (2.88%), δ-cadinene (2.52%), and 1,4-cadadiene (2.04%). The main chemical class of the essential oil was terpenoids, which represent 71.65%, followed by hydrocarbons (26.31%). A total of 50 components were identified, among these β-caryophyllene was found to be dominant, which has great medicinal value, and some other compounds were also identified for the first time in the essential oil of P. guajava leaves.

Opportunities and challenges for the sustainable production of structurally complex diterpenoids in recombinant microbial systems

With over 50.000 identified compounds terpenes are the largest and most structurally diverse group of natural products. They are ubiquitous in bacteria, plants, animals and fungi, conducting several biological functions such as cell wall components or defense mechanisms. Industrial applications entail among others pharmaceuticals, food additives, vitamins, fragrances, fuels and fuel additives. Central building blocks of all terpenes are the isoprenoid compounds isopentenyl diphosphate and dimethylallyl diphosphate. Bacteria like Escherichia coli harbor a native metabolic pathway for these isoprenoids that is quite amenable for genetic engineering. Together with recombinant terpene biosynthesis modules, they are very suitable hosts for heterologous production of high value terpenes. Yet, in contrast to the number of extracted and characterized terpenes, little is known about the specific biosynthetic enzymes that are involved especially in the formation of highly functionalized compounds. Novel approaches discussed in this review include metabolic engineering as well as site-directed mutagenesis to expand the natural terpene landscape. Focusing mainly on the validation of successful integration of engineered biosynthetic pathways into optimized terpene producing Escherichia coli, this review shall give an insight in recent progresses regarding manipulation of mostly diterpene synthases.